The term IN-BOX CONTENTS refers to the items that are stored in an inbox, which is a folder or area of an email account or other messaging system. The crossword solutions for this term are EMAIL (5 letters), MAIL (4 letters), and EMAILS (6 letters). EMAIL is a form of electronic communication that is sent and received over the internet, while MAIL is a physical form of communication that is sent through the postal service. EMAILS is the plural form of EMAIL.